Improve x264, vorbis and theora codecs

Added `quality` option for x264, vorbis and theroa codecs and `preset` option for x264.

Also removed confusing unnecessary x264 options. (It's better to use presets)
From http://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide:
> You can overwrite default preset settings with the x264opts option or by using the libx264 private options (see libx264 AVOptions in ffmpeg -h full). This is **not recommended** unless you know what you are doing. The presets were created by the x264 developers and tweaking values to get a better output is **usually a waste of time**.